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Danish et al. BMC Plant Biology (2024) 24:139
https://doi.org/10.1186/s12870-024-04843-w BMC Plant Biology
*Correspondence:
Subhan Danish
sd96850@gmail.com
Shah Fahad
shah_fahad80@yahoo.com
1Department of Soil Science, Faculty of Agricultural Sciences and
Technology, Bahauddin Zakariya University, Multan, Punjab, Pakistan
2Department of Agronomy, Pir Mehr Ali Shah Arid Agriculture University,
Rawalpindi, Pakistan
3Department of Soil and Environmental Science, the University of
Agriculture Peshawar, Peshawar, Pakistan
4Department of Agronomy, Abdul Wali Khan University Mardan, Mardan,
Khyber Pakhtunkhwa 23200, Pakistan
5Department of Natural Sciences, Lebanese American University, Byblos,
Lebanon
6Department of Agricultural Engineering, Khwaja Fareed University of
Engineering and Information Technology Rahim Yar Khan, Rahim Yar
Khan, Punjab 64200, Pakistan
7Department of Botany and Microbiology, College of Science, King Saud
University, PO Box -2455, Riyadh 11451, Saudi Arabia
8Department of Botany, Hindu College Moradabad (Mahatma Jyotiba
Phule Rohilkhand University Bareilly), Moradabad 244001, India
Abstract
Drought stress poses a signicant challenge to maize production, leading to substantial harm to crop growth and
yield due to the induction of oxidative stress. Deashed biochar (DAB) in combination with carboxymethyl cellulose
(CMC) presents an eective approach for addressing this problem. DAB improves soil structure by increasing
porosity and water retention and enhancing plant nutrient utilization eciency. The CMC provides advantages
to plants by enhancing soil water retention, improving soil structure, and increasing moisture availability to the
plant roots. The present study was conducted to investigate the eects of DAB and CMC amendments on maize
under eld capacity (70 FC) and drought stress. Six dierent treatments were implemented in this study, namely
0 DAB + 0CMC, 25 CMC, 0.5 DAB, 0.5 DAB + 25 CMC, 1 DAB, and 1 DAB + 25 CMC, each with six replications, and
they were arranged according to a completely randomized design. Results showed that 1 DAB + 25 CMC caused
signicant enhancement in maize shoot fresh weight (24.53%), shoot dry weight (38.47%), shoot length (32.23%),
root fresh weight (19.03%), root dry weight (87.50%) and root length (69.80%) over control under drought
stress. A substantial increase in maize chlorophyll a (40.26%), chlorophyll b (26.92%), total chlorophyll (30.56%),
photosynthetic rate (21.35%), transpiration rate (32.61%), and stomatal conductance (91.57%) under drought stress
showed the eciency of 1 DAB + 25 CMC treatment compared to the control. The enhancement in N, P, and K
concentrations in both the root and shoot validated the eectiveness of the performance of the 1 DAB + 25 CMC
treatment when compared to the control group under drought stress. In conclusion, it is recommended that the
application of 1 DAB + 25 CMC serves as a benecial amendment for alleviating drought stress in maize.
Keywords Soil amendments, Crop resilience, Water retention, Plant performance, Environmental stress mitigation
Enhancing maize resilience to drought stress:
the synergistic impact of deashed biochar
and carboxymethyl cellulose amendment
SubhanDanish1*, ZuhairHasnain2, KhadimDawar3, ShahFahad4,5*, Adnan NoorShah6, Saleh H.Salmen7 and
Mohammad JavedAnsari8
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Page 2 of 20
Danish et al. BMC Plant Biology (2024) 24:139
Introduction
Drought poses a signicant threat to maize production,
aecting yield and quality [1–3]. Maize is highly vulner-
able to water stress during crucial growth stages, leading
to stunted growth and reduced yields [4, 5]. is empha-
sizes the need for adaptive measures, such as water-e-
cient farming practices, to safeguard global food security
[6].
Existing approaches seek to address the challenges
posed by drought in maize production by promoting
water-ecient farming methods. However, the wide-
spread adoption of these solutions encounters signicant
obstacles [7–9]. On the other hand, considerable time
and nancial resources needed for researching and devel-
oping resilient maize varieties present accessibility chal-
lenges for farmers [10, 11].
Carboxymethyl cellulose (CMC) is a cellulose deriva-
tive, which is a modied form of cellulose, a naturally
occurring polymer found in the cell walls of plants [12].
It plays a vital role in alleviating the impact of drought
conditions in agriculture. As a derivative of water-soluble
cellulose, CMC enhances soil water retention, thereby
improving its ability to retain moisture. Whether applied
to soil or used as a seed coating, CMC serves as a protec-
tive layer that helps seeds retain essential moisture and
nutrients crucial for germination and early plant growth,
particularly in regions prone to drought [12]. Moreover,
CMC contributes to enhancing soil structure, preventing
compaction, and facilitating improved water inltration
[13]. ese attributes establish CMC as a valuable tool for
bolstering crop resilience to water scarcity and support-
ing the implementation of sustainable agricultural prac-
tices in drought-aected areas [14].
Biochar, generated by the thermal breakdown of
organic biomass, is a carbon-rich, porous substance
utilized as a sustainable soil enhancer to enhance agri-
cultural productivity and facilitate carbon sequestra-
tion [8, 15–17]. Deashed biochar (DAB) is biochar that
has undergone a treatment to minimize or eliminate its
ash content [18]. It plays a crucial role in drought con-
ditions by improving water retention in the soil through
its porous structure, serving as a reservoir for plant mois-
ture. Additionally, biochar acts as a nutrient sponge, pre-
venting nutrient leaching and ensuring essential elements
are available to plants even in water-scarce environments
[18]. Its incorporation into the soil also contributes to
enhanced soil structure, promoting better water inl-
tration and mitigating the adverse eects of drought on
plant growth [19].
e combined application of CMC and deashed bio-
char requires comprehensive investigations to identify
their role in the drought-stress environment under the
maize production system [20]. e study hypothesized
that the combined application of CMC and deashed
biochar would improve maize productivity as compared
to their individual eects. e main objective of the
study was to evaluate the Impact of CMC and deashed
biochar on the growth, physiological, and yield attributes
of the maize under drought normal and drought stress
conditions.
Materials and methods
Preparation of biochar
Cotton sticks were used as a waste product in the bio-
char synthesis process, and they were pyrolyzed at a tem-
perature of 440°Cfor 120 min. e physical, chemical,
and nutritional characteristics of the produced biochar
were next evaluated. e biochar was then cooled, then
it wasgrinded to a size of 2mm and placed in storage for
later use.
Deashing of biochar
e initial step involved rinsing the raw biochar with
deionized water to eliminate water-soluble ash constitu-
ents. is rinsing procedure comprised immersing the
biochar in water and employing repetitive ltration (a
total of six times) to distinguish the biochar from the liq-
uid. Following the rinsing process, excess moisture was
eliminated by drying the biochar. Subsequently, the dried
biochar underwent sieving using a sieve with a mesh
size of less than 2mm to attain a consistent particle size
distribution.
Characterization of biochar
Gravimetric analysis was used to identify the content of
the biochar in accordance with the approach outlined
by [21]. In order to measure the biochar’s pH [22] and
electrical conductivity (EC) [23], a 1:10 combination of
biochar and distilled water was made. To assess the nitro-
gen (N) content, the biochar samples were subjected to
digestion and distilled, utilising the Kjeldahl distillation
technique [24]. Using HNO3-HClO4, biochar sample
as digested and then phosphate (P) and potassium (K)
concentrations in the biochar were evaluated [25]. en,
utilizing a spectrophotometer and the ammonium vana-
date-ammonium molybdate yellow color procedure, the
phosphorus (P) content was determined. A ame pho-
tometer was used to measure the potassium (K+) content
[26]. Table1 lists the physicochemical features of biochar.
Carboxymethyl cellulose
Carboxymethyl cellulose (CMC) was procured from a
certied local supplier of Sigma-Aldrich. e CMC prod-
uct details are as follows: Product Number: PHR2726-
2G, Lot Number: LRAD6430, Physical Form: Solid,
Color: White.
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Page 3 of 20
Danish et al. BMC Plant Biology (2024) 24:139
Treatments and experimental plan
ere were 3 levels of deashed biochar (DAB) applied in
the soil. e DAB levels include 0, 0.5% and 1.0%. Two
levels of CMC were applied as foliar, i.e., 0 and 25mM. All
the treatments were applied on the maize plants under
no drought stress (70%FC) and drought stress (40%FC)
following a completely randomized design (CRD). e
climatic data of the experimental site is provided in Fig.1.
Seeds collection and sterilization
e maize seeds (Cimmyt-Pak) utilized in the present
research came from a licensed seed supplier who was
approved by the Punjab government in Pakistan. Only
strong, healthy seeds were chosen to verify the seeds’
integrity; broken and weak seeds were not included. e
chosen seeds underwent a surface-sterilization proce-
dure before being sown. To do this, the seeds were rst
treated with a 5% solution of sodium hypochlorite, fol-
lowed by three washings with 95% ethanol. e seeds
were then rinsed three times in sterilized deionized water
to eliminate any remaining sterilizing chemicals [27].
Seeds sowing and thinning
A total of 10 seeds were sown, in each pot containing
15kg of soil. After germination, the number of seedlings
in each pot was reduced to 2 through thinning.
Drought
In order to investigate the eects of drought stress on
maize plant physiology and growth, a controlled experi-
ment was designed to establish two distinct soil moisture
conditions: a no drought stress condition referred to as
70% eld capacity (70FC) and drought stress (DS) condi-
tion denoted as 40% eld capacity (40FC) [28].
Data gathering and harvesting
Plants were collected for data collection after 50 days of
sowing. Weights of fresh shoot and roots were measured
soon after harvest. Samples were oven-dried at 65°C for
72 h to get consistent weight for determining the dry
mass of the shoot and roots.
Chlorophyll contents and carotenoids
Arnon’s approach was used for the determination of
chlorophyll a, chlorophyll b, and total chlorophyll in fresh
maize leaves [29]. A mixture of 80% acetone was used
for the extraction. For chlorophyll a and b, absorbance
measurements were made at wavelengths of 663nm and
645nm, respectively.
Chlorophylla
mg
g
=
(12.7×A663) −(2.69 ×A645)×V
1000
×W
Chlorophyllb
mg
g
=
(22.9×A645)−(4.68 ×A663) ×V
1000 ×W
Tota
lChlorophyll
mg
g
=20.2(OD645) +8.02 (OD663) ×V/1000 (W
)
Gas exchange characteristics
e CI-340 Photosynthesis system by CID, Inc. USA was
used as the infrared gas analyzer for determining the
leaf’s stomatal conductivity, net rate of photosynthetic
activity, and net transpiration rate, respectively. Within
10:30 and 11:30 a.m. on a bright day, while the light level
was sucient for photosynthesis, assessments were made
[30].
SOD
e inhibition of nitro blue tetrazolium (NBT) reduction
was studied to ascertain SOD activity. e absorbance
was taken at 560nm. [31].
POD
Observing the oxidation of an appropriate substrate,
including guaiacol or o-dianisidine, was used to measure
POD activity. At 420 nm wavelength, the rise in absor-
bance brought on by substrate oxidation was quantied
[32].
CAT
Catalase (CAT) activity was quantied by measuring the
breakdown of hydrogen peroxide H2O2 and the subse-
quent reduction in absorbance at 240 nm, indicative of
H2O2 decomposition.
Table 1 Pre-experimental soil, biochar and irrigation water
characteristics
Soil Values Biochar Values Irrigation Values
pH 8.01 pH 7.11 pH 7.21
SOC (%) 0.60 ECe (dS/m) 3.39 EC (µS/cm) 301
TN (%) 0.030 Volatile Mat-
ter (%)
45 Carbonates
(meq./L)
0.00
EP (mg/
kg)
4.12 Fixed carbon
(%)
55 Bicarbonates
(meq./L)
4.19
AK (mg/
kg)
107 TN (%) 0.05 Chloride
(meq./L)
0.15
Sand (%) 25 TP (%) 0.01 Ca + Mg
(meq./L)
3.95
Silt (%) 40 TK (%) 0.02 Sodium
(mg/L)
171
Clay (%) 35 Surface area
(m²/g)
450 TN = Total Nitrogen
EP = Extractable
Phosphorus
AK = Available
Potassium
CEC = Cation Ex-
change Capacity
Texture Clay Loam CEC
(meq./100g)
500
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Danish et al. BMC Plant Biology (2024) 24:139
APX
e oxidation of ascorbate in the presence of H2O2 was
observed for APX activity at 240 nm [33]. e oxidation
of ascorbate in the presence of H2O2 was observed for
APX activity.
MDA
e MDA, was measured by forming a colored com-
pound by reacting the sample extract with thiobarbituric
acid (TBA). e complex’s absorption was determinedat
532 nm.
Electrolyte leakage
e leaves were rst washed with water that was deion-
ized to get rid of any exterior pollutants before the test-
ing was done. en, utilizing a steel cylinder with a 1cm
diameter, uniform-sized leaf pieces measuring around
one gram were produced. e leaf fragments were next
put into several tubes for testing with 20 ml of deion-
ized water. To facilitate the passage of electrolytes from
the leaf tissues into the water, the test tubes were left to
incubate at 25°C for 24h. An EC meter that was already
validated was used to test the water solution’s electrical
properties (EC1) after the incubation time. e test tubes
Fig. 1 Climatic data of the experimental site
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Page 5 of 20
Danish et al. BMC Plant Biology (2024) 24:139
were then heated in a water bath for 20min at 120°C to
measure the second electrical conductivity (EC2) (Lutts
et al., 1996).
Electrolyte
leakage (%)=
EC1
EC2×
100
Statistical analysis
Analysis of variance was applied to assess the collected
data was statistically analyzed in R Software (Version)
using a linear mixed model [34]. ANOVA values are pro-
vided in Tables2 and 3. e means were compared using
Tukey multiple comparison tests at p < 0.05. e gures
were created using origin software.
Results
Shoot length, shoot fresh and dry weight
In the absence of both DAB and CMC (70 FC, 0 DAB + 0
CMC), the mean shoot length was 38.09 cm. However,
when CMC was added, there was a noticeable percent-
age increase of 16.96% in shoot length over the control (0
DAB + 0 CMC) under 70 FC. In contrast, the application
of 0.5 DAB resulted in a 9.11% increase in shoot length
from the control (0 DAB + 0 CMC) under no stress.
When both 0.5 DAB and 25 CMC were applied, a signi-
cant 28.43% increase was observed in the shoot length
over the control under no drought stress (70 FC). Finally,
under 70 FC conditions, treatment 1 DAB showed 5.17%
increase in the shoot length as compared to the control.
When 1 DAB was combined with 25CMC there was a
remarkable 24.36% increase in shoot length related to the
control under no drought stress (70 FC). Under drought
stress conditions with no DAB and CMC, the mean shoot
length was 26.90cm. However, when 25 CMC treatment
was added under drought stress, there was a signicant
20.04% increase in the shoot length observed over the
control under drought stress. Similarly, the application of
treatment 0.5 DAB under drought stress led to a 6.32%
increase in the shoot length from the control. When
both 0.5 DAB and 25 CMC treatments were combined,
26.17% increase in shoot length was recorded parallel to
the control under drought stress. Moreover, 1 DAB treat-
ment under drought stress conditions showed 13.46%
rise in the shoot length with respect to the control. When
1 DAB was combined with 25 CMC, there was a remark-
able 32.23% increase, resulting in the shoot length related
to the control in drought stress.
e average shoot fresh weight was 170.92g/plant when
DAB and CMC under 0 DAB and 0 CMC in 70 Fc condi-
tion. Under 70 FC, in comparison to the control group
(0 DAB + 0 CMC), the application of 25 CMC resulted in
a signicant 5.63% increase in shoot fresh weight. Simi-
larly, the use of 0.5 DAB led to a 3.81% increase, while the
Table 2 P-value of main and interaction eect of deashed biochar (DAB) and carboxymethyl cellulose (CMC) on shoot length, shoot fresh weight, shoot dry weight, root fresh
weight, root dry weight, root length, number of leaves, leaf fresh weight, leaf dry weight, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids and root potassium under no
drought and drought stress
Treatments Shoot
length
Shoot
fresh
weight
Shoot dry
weight
Root fresh
weight
Root dry
weight
Root
length
Number
of leaves
Leave fresh
weight
Leave dry
weight
Chloro-
phyll a
Chloro-
phyll b
Total
chloro-
phyll
Carot-
enoids
Root
potas-
sium
No Drought Stress
DAB 0.01 < 0.01 0.01 0.04 0.04 0.11 0.21 0.13 0.11 0.11 0.02 0.08 0.10 0.02
CMC < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01
DAB×CMC 0.62 0.33 0.40 0.26 0.82 0.97 0.65 0.76 0.87 0.81 0.63 0.46 0.67 0.51
Drought Stress
DAB < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01
CMC < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01
DAB×CMC 0.25 0.27 0.01 0.01 0.12 0.21 0.36 0.36 0.01 0.01 0.19 0.01 0.02 0.522
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Danish et al. BMC Plant Biology (2024) 24:139
combination of 0.5 DAB and 25 CMC showed a substan-
tial 12.94% increase in shoot fresh weight parallel to the
control under 70 FC. However, when 1 DAB treatment
was applied, there was only a modest 2.40% increase in
shoot fresh weight compared to the control in the 70 FC
condition. e most signicant increase was observed
when 1 DAB was combined with 25 CMC, resulting in
a notable 10.41% rise in shoot fresh weight compared
to the control under no drought stress (70 FC). In com-
parison to the drought stress control group (0 DAB + 0
CMC), the application of 25 CMC led to a remarkable
14.21% increase in shoot fresh weight. Additionally, 0.5
DAB treatment resulted in a 4.50% increase, while the
combination of 0.5 DAB and 25 CMC showed a substan-
tial 18.94% increase in shoot fresh weight over the con-
trol under drought stress. Furthermore, when 1 DAB was
applied during drought stress, there was a notable 9.33%
increase in shoot fresh weight compared to the control.
e most signicant increase was observed with the
combination of 1 DAB and 25 CMC, which resulted in a
remarkable 24.53% rise in shoot fresh weight contrasted
to the control under drought stress conditions.
In a 70 FC circumstances, the control group with no
DAB and CMC (0 DAB + 0 CMC) had a mean shoot dry
weight of 17.25g/plant. When 25 CMC was introduced,
there was a noTable14.49% increase in shoot dry weight
linked to the control under no stress (70 FC). Similarly,
the application of 0.5 DAB resulted in a 10.43% increase
in shoot dry weight over the control under the same 70
FC conditions. Combining 0.5 DAB with 25 CMC treat-
ment under no drought stress (70 FC), led to a substan-
tial 24.23% increase in shoot dry weight contrasted to the
control. e 1 DAB treatment showed a signicant 4.00%
increase in shoot dry weight, and when 1 DAB was com-
bined with 25 CMC, there was a noTable22.32% increase
relative to the control under 70FC conditions. Under
drought stress conditions, the control group (0 DAB + 0
CMC) had a mean shoot dry weight of 11.93g/plant. e
addition of 25 CMC during drought stress resulted in a
signicant 24.98% increase in shoot dry weight compared
to the control. In comparison to the baseline treatment,
the application of 0.5 DAB treatment led to a 12.15%
increase in shoot dry weight under drought stress. When
0.5 DAB was combined with 25 CMC during drought
stress, a remarkable 31.10% increase in shoot dry weight
was observed compared to the control. e 1 DAB treat-
ment exhibited a 22.05% increase, and when 1 DAB was
combined with 25 CMC, there was a substantial 38.47%
increase in shoot dry weight relative to the control during
drought stress (Table4).
Root fresh weight
Under 70FC (no drought stress), the control group (0
DAB + 0 CMC) exhibited a mean root fresh weight of
Table 3 P-value of main and interaction eect of deashed biochar (DAB) and carboxymethyl cellulose (CMC) on photosynthetic rate, transpiration rate,, stomatal conductance, leaves
nitrogen, leaves phosphorus, leaves potassium, root nitrogen, electrolyte leakage, POD, SOD, catalase, ascorbic acid, H2O2, MDA and root phosphorus under no drought and drought
stress
Treatments Photo-
synthet-
ic rate
Transpi-
ration
rate
Stomatal
conduc-
tance
Leave
Nitrogen
Leave
Phospho-
rus
Leave
Potassium
Root
Nitrogen
Electrical
Leakage
POD SOD Catalase Ascor-
bic acid
H2O2MDA Root
Phos-
phorus
No Drought Stress
DAB 0.10 0.18 0.06 0.016 0.01 0.09 0.02 < 0.02 0.09 0.12 0.01 0.01 0.08 0.02 0.11
CMC < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01
DAB×CMC 0.85 0.99 0.76 0.76 0.60 0.51 0.02 0.92 0.48 0.284 0.49 0.08 0.93 0.95 1.00
Drought Stress
DAB < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001
CMC < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001
DAB×CMC 0.54 < 0.001 0.041 1.00 0.04 0.017 < 0.001 < 0.001 < 0.001 0.587 0.587 0.539 0.199 0.11 0.02
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Danish et al. BMC Plant Biology (2024) 24:139
25.71g/plant. When 25 CMC was introduced under the
70 FC conditions, there was a signicant 16.84% increase
and the application of 0.5 DAB, indicating a 10.42%
increase in root fresh weight compared to the control.
e combination of 0.5DAB and 25 CMC resulted in a
remarkable 33.10% increase in root fresh weight, con-
trasting to the control (70 FC). In contrast, when 1 DAB
was applied under no stress (70 FC), representing a mod-
est 3.11% increase in root fresh weight over the control.
However, combining 1 DAB with 25 CMC as compared
to the control led to a more substantial 26.95% increase
in root fresh weight under 70FC conditions. During
drought stress conditions, the control group (0 DAB + 0
CMC) exhibited a mean root fresh weight of 20.60 g/
plant. e introduction of 25 CMC under drought stress
resulted in an 8.25% increase, and treatment 0.5 DAB
showed a slight 2.82% increase in root fresh weight
assessed to the control. e combination of 0.5 DAB and
25 CMC yielded a 14.95% increase in root fresh weight
than the control under drought stress. Similarly, using
1DAB during drought stress conditions represented
a 5.44% increase in root fresh weight over the con-
trol. When 1 DAB was combined with 25 CMC during
drought stress, there was a substantial 19.03% increase in
root fresh weight from the control.
Root dry weight
e root dry weight was measured 4.54g/plant under no
drought stress (40 FC) with no DAB and CMC (0 DAB + 0
CMC). When 25 CMC was introduced under 70 FC con-
ditions, there was a notable 34.80% increase in root dry
weight over the control. Applying 0.5 DAB treatment
resulted in a 15.64% increase in root dry weight over
the control (0 DAB + 0 CMC). Combining 0.5 DAB with
25 CMC led to a substantial 48.02% increase, and using
1DAB treatment in the 70 FC condition reected an
8.15% increase in root dry weight matched to the control.
Furthermore, when 1 DAB was combined with 25 CMC
under 70 FC conditions, a signicant 41.41% increase
in root dry weight was observed over the control under
no stress (70 FC). Under drought stress conditions with
no DAB and CMC (0DAB + 0 CMC), the mean root dry
weight was 2.24g/plant. However, when 25 CMC treat-
ment was applied during drought stress, there was a
substantial 48.66% increase in root dry weight from the
control group. Using 0.5 DAB treatment during drought
Table 4 The eect of carboxymethyl cellulose (CMC) and deashed biochar (DAB) on shoot and root length, shoot and root fresh and
dry weights of maize cultivated under no drought and drought stress
DAB (%) Shoot Length (cm) Shoot Fresh Weight (g) Shoot Dry Weight (g)
0 CMC 25 CMC 0 CMC 25 CMC 0 CMC 25 CMC
Field Capacity 70
038.09 ± 0.67a 44.55 ± 1.21c 170.92 ± 1.76a 180.55 ± 1.79 c 17.25 ± 0.16a 19.75 ± 0.46b
0.5 41.56 ± 0.95b 48.92 ± 0.13d 177.44 ± 0.97bc 193.04 ± 1.75e 19.05 ± 0.14b 21.43 ± 0.17c
1.0 40.06 ± 0.49b 47.37 ± 0.64d 175.02 ± 1.32b 188.71 ± 1.93d 17.94 ± 0.59a 21.1 ± 0.16c
Drought Stress
028.6 ± 0.24b 33.94 ± 0.53e 134.8 ± 1.25b 153.43 ± 2.19e 13.38 ± 0.59b 15.64 ± 0.47d
0.5 30.52 ± 0.65c 35.57 ± 0.95f 141.04 ± 1.05c 160.64 ± 3.08f 14.56 ± 0.18c 16.52 ± 0.3e
1.0 26.9 ± 0.67a 32.29 ± 0.65d 129 ± 3.39a 147.33 ± 2.75d 11.93 ± 0.7a 14.91 ± 0.08c
DAB (%) Root Length (cm) Root Fresh Weight (g) Root Dry weight (g)
Field Capacity 70
018.72 ± 0.21a 21.72 ± 0.46bc 25.71 ± 0.29a 30.04 ± 0.33c 4.54 ± 0.06a 6.12 ± 0.21c
0.5 20.77 ± 0.40b 23.45 ± 0.80d 28.39 ± 0.26b 34.22 ± 0.34e 5.25 ± 0.17b 6.72 ± 0.19d
1.0 19.52 ± 0.39a 22.49 ± 0.24cd 26.51 ± 0.31a 32.64 ± 1.24d 4.91 ± 0.02b 6.42 ± 0.05cd
Drought Stress
011.33 ± 0.22b 16.11 ± 0.31e 20.60 ± 0.17a 22.30 ± 0.28d 2.24 ± 0.15a 3.33 ± 0.10d
0.5 13.22 ± 0.64c 17.54 ± 0.43f 21.18 ± 0.13b 23.68 ± 0.54e 2.54 ± 0.18b 3.98 ± 0.04e
1.0 10.33 ± 0.24a 14.99 ± 0.56d 21.72 ± 0.25c 24.52 ± 0.29f 2.94 ± 0.06c 4.20 ± 0.16f
DAB (%) Number of leaves Leave Fresh weight (g) Leave Dry weight (g)
Field Capacity 70
08.16 ± 0.07a 9.3 ± 0.11c 41.08 ± 1.27a 47.36 ± 1.2c 8.14 ± 0.18a 10.57 ± 0.18c
0.5 8.77 ± 0.11b 9.79 ± 0.2d 44.81 ± 0.54b 54.38 ± 0.74 e 9.82 ± 0.57b 11.63 ± 0.20d
1.0 8.28 ± 0.04a 9.54 ± 0.04cd 42.81 ± 0.39ab 49.9 ± 0.61d 8.77 ± 0.14 a 11.08 ± 0.16cd
Drought Stress
028.6 ± 0.24b 33.94 ± 0.53e 134.8 ± 1.25b 153.43 ± 2.19e 13.38 ± 0.59b 15.64 ± 0.47d
0.5 30.52 ± 0.65c 35.57 ± 0.95f 141.04 ± 1.05c 160.64 ± 3.08f 14.56 ± 0.18c 16.52 ± 0.3e
1.0 26.9 ± 0.67a 32.29 ± 0.65d 129 ± 3.39a 147.33 ± 2.75d 11.93 ± 0.7a 14.91 ± 0.08c
Values are mean ± standard deviation (n = 3)
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Page 8 of 20
Danish et al. BMC Plant Biology (2024) 24:139
stress represents a 13.39% increase in root dry weight
over the control. Combining 0.5 DAB with 25 CMC dur-
ing drought stress induced a remarkable 77.68% increase
in root dry weight in comparison to the control. Employ-
ing 1 DAB treatment during drought stress conditions
resulted in a 31.25% increase in root dry weight associ-
ated to the control. Furthermore, when 1 DAB was com-
bined with 25 CMC during drought stress, a signicant
87.50% increase in root dry weight was observed related
to the control.
Root length, number of leaves, leaves fresh and dry
weights
e control group (0 DAB + 0 CMC) exhibited an aver-
age root length of 18.72 cm under 70 FC conditions.
When 25 CMC treatment was introduced to the plant,
there was a notable 16.03% increase in root length over
the control treatment under no drought stress (70 FC).
Similarly, the application of 0.5 DAB resulted in a 10.95%
increase in the root length evaluated to the control under
no drought stress (70 FC). e combined treatment of 0.5
DAB and 25 CMC showed a substantial 25.27% increase
in root length under no drought stress (70 FC) over the
control. On the other hand, the 1DAB treatment yielded
a modest 4.27% increase in root length related to the
control. However, when 1 DAB was combined with 25
CMC, a more signicant 20.14% increase in root length
was observed under 70 FC over the control. In contrast,
under drought stress conditions, the control group (0
DAB + 0 CMC) had an average root length of 10.33cm.
e introduction of 25 CMC led to a remarkable 45.11%
increase in root length under drought stress over the
control. Similarly, the application of 0.5 DAB represents
a 9.68% increase in root length linked to the control. e
combined treatment of 0.5 DAB and 25 CMC showed
a substantial 55.95% increase in root length, and on the
other hand, the 1 DAB treatment corresponded to a
notable 27.98% increase in root length from the control
under no drought stress. When 1 DAB was combined
with 25 CMC during drought stress, a remarkable 69.80%
increase in root length was observed, contrasting with
the control.
Under 70F C conditions, the application of 25 CMC
led to a notable 13.97% increase in the number of leaves
compared to the control (0 DAB + 0 CMC). Similarly,
when 0.5DAB was applied under 70 FC, there was a
7.48% increase in the number of leaves in comparison to
the control. Combining 0.5 DAB with 25 CMC resulted in
a signicant 19.98% increase in the number of leaves con-
trasted to the control under 70 FC. On the other hand,
the use of 1 DAB showed a modest 1.47% increase in the
number of leaves competed to the control under 70 FC
conditions. When 1 DAB was combined with 25 CMC,
a 16.91% increase in the number of leaves was observed
relative to the control under the 70 FC stress conditions.
Under drought stress conditions, the control group of
the leaves number was recorded 5.12. e application of
25 CMC during drought stress resulted in a substantial
33.98% increase in the number of leaves evaluated to the
control. Likewise, the control using 0.5 DAB treatment
led to an 8.98% increase in the number of leaves during
drought stress. Combining 0.5DAB with 25 CMC caused
a remarkable 43.16% increase in the number of leaves
equaled to the control under drought stress conditions.
Furthermore, the application of 1 DAB showed a 21.29%
increase in the number of leaves matched to the con-
trol under drought stress. When 1 DAB was combined
with 25 CMC during drought stress, there was a striking
53.13% increase in the number of leaves relative to the
control.
Under no drought stress (70 FC) with no DAB and
CMC (0 DAB + 0 CMC), the mean leaves fresh weight
was 41.08g/plant. When 25 CMC was introduced under
the 70FC conditions, there was a notable 15.29% increase
in leaves fresh weight compared to the control. Similarly,
applying 0.5 DAB resulted in a 9.08% increase in leaves
fresh weight relative to the control, while combining 0.5
DAB with 25 CMC led to a substantial 32.38% increase
under no drought stress (70 FC). e use of 1 DAB under
70 FC conditions resulted in a signicant 4.21% increase
in leaves fresh weight related to the control, and when
1 DAB was combined with 25 CMC, a 21.47% increase
was observed. Under drought stress conditions, without
DAB and CMC (0 DAB + 0 CMC), the mean leaves fresh
weight was 26.27g/plant. However, the application of 25
CMC during drought stress induced a signicant 33.35%
increase in leaves fresh weight associated to the control
under the drought stress conditions. Using 0.5 DAB dur-
ing drought stress led to a 14.24% increase in leaves fresh
weight related to the control, and when 0.5 DAB was
combined with 25 CMC, a substantial 40.20% increase in
fresh weight was recorded relative to the control. Simi-
larly, the use of 1 DAB during drought stress conditions
resulted in a 22.23% increase in fresh weight equated
to the control, and when 1 DAB was combined with 25
CMC, a remarkable 47.16% increase in fresh weight was
observed related to the control.
e mean leaf dry weight for the control group (0
DAB + 0 CMC) at 70 FC conditions was 8.14 g/plant.
However, when 25 CMC treatment was introduced to the
plant, there was a signicant 29.85% increase in leaves
dry weight under no drought stress (70 FC) over the con-
trol group. Similarly, under no drought stress (70 FC), the
application of 0.5DAB resulted in a 20.64% increase in
dry weight linked to the control. Combining 0.5DAB with
25 CMC treatment exhibited the most substantial 42.87%
boost in dry weight over the control under no drought
stress (70 FC). On the other hand, 1 DAB treatment
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Page 9 of 20
Danish et al. BMC Plant Biology (2024) 24:139
showed a modest 7.74% increase in dry weight, and when
combined with 25 CMC, it yielded a 36.12% increase in
dry weight under 70 FC conditions in comparison to the
control treatment. Under drought stress conditions, the
control group (0 DAB + 0 CMC) had a mean dry weight
of 5.11 g/plant. e introduction of 25 CMC during
drought stress resulted in a 29.35% increase in dry weight
over the control. Similarly, 0.5 DAB treatment showed a
6.46% increase in dry weight related to the control under
drought stress. e combination of 0.5 DAB with 25
CMC treatment compared to the control demonstrated
a substantial 40.12% increase in dry weight. In contrast to
the control, 1 DAB treatment displayed a 13.11% increase
in dry weight, and when combined with 25 CMC during
drought stress, it exhibited a remarkable 50.29% increase
in dry weight under drought stress (Table5).
Chlorophyll a, b, total chlorophyll and carotenoids
In 70 FC conditions, the control group (0 DAB + 0 CMC)
exhibited chlorophyll a level of 1.18mg/g. ere was a
substantial 14.41% increase in chlorophyll a content from
the control when treatment 25 CMC was applied to the
plant in the 70 FC (no drought stress). Like the control
group, the administration of 0.5DAB in the absence of
stress (70FC) increased the chlorophyll a content by
11.02%. Combining 0.5 DAB with 25 CMC treatment
in the 70FC condition resulted in a remarkable 22.03%
increase in chlorophyll a content related to the con-
trol. e use of 1 DAB under 70 FC conditions yielded
a modest 4.24% increase in chlorophyll a content from
the control. However, when 1 DAB was combined with
25 CMC in the same conditions, there was a signicant
17.80% increase in chlorophyll a content contrasting
to the control. In contrast, under drought stress con-
ditions, the control group (0 DAB + 0 CMC) displayed
chlorophyll a content of 0.77mg/g. e introduction of
25 CMC during drought stress resulted in a substantial
24.68% increase in chlorophyll a content from the con-
trol. Applying 0.5 DAB during drought stress caused a
moderate 5.19% increase in chlorophyll a content in com-
parison to the control. Combining 0.5 DAB with 25 CMC
contrasting with the control under drought stress condi-
tions led to a signicant 31.17% increase in chlorophyll a
content. Similarly, the use of 1 DAB during drought stress
conditions produced an 18.18% increase, and treatment 1
DAB was combined with 25 CMC in the drought stress
conditions, there was a remarkable 40.26% increase in the
chlorophyll a content in contrast to the control.
e chlorophyll b content of the control (0 DAB + 0
CMC) group was measured to be 0.34mg/g in a non-
stressful condition (70 FC). When 25 CMC was applied
under 70FC conditions, there was a 5.88% increase in
chlorophyll b content from the control, and the appli-
cation of 0.5 DAB resulted in the same 5.88% increase.
However, the combination of 0.5 DAB and 25 CMC led
to a more substantial increase of 11.76% in chlorophyll
b content estimated to the control under no drought
stress (70 FC). On the other hand, the 1 DAB treatment
showed no change in chlorophyll b content relative to the
control under 7 0FC conditions, and when 1 DAB was
combined with 25 CMC, there was an 11.76% increase in
chlorophyll b content. Under drought stress conditions,
Table 5 The eect of carboxymethyl cellulose (CMC) and deashed biochar (DAB) on chlorophyll a, b, total, carotenoids and electrolyte
leakage of maize cultivated under no drought and drought stress
DAB (%) Chlorophyll a (mg g− 1) Chlorophyll b (mg g− 1) Total Chlorophyll (mg g− 1) Carotenoids (mg g− 1)
0 CMC 25 CMC 0 CMC 0 CMC 0 CMC 25 CMC 0 CMC 25 CMC
Field Capacity 70
01.23 ± 0.03a 1.23 ± 0.03a 0.34 ± 0.01a 0.36 ± 0.01c 1.48 ± 0.03a 1.68 ± 0.02d 0.76 ± 0.01a 0.83 ± 0.01c
0.5 1.39 ± 0.02cd 1.39 ± 0.02cd 0.36 ± 0.01bc 0.38 ± 0.01d 1.61 ± 0.04c 1.79 ± 0.02e 0.81 ± 0.01b 0.88 ± 0.01d
1.0 1.23 ± 0.03a 1.23 ± 0.03a 0.34 ± 0.01ab 0.38 ± 0.01d 1.56 ± 0.02b 1.71 ± 0.01d 0.77 ± 0.01a 0.86 ± 0.01d
Drought Stress
00.77 ± 0.01a 0.96 ± 0.02d 0.26 ± 0.01a 0.3 ± 0.01d 1.08 ± 0.03a 1.29 ± 0.03d 0.31 ± 0.03a 0.52 ± 0.04d
0.5 0.81 ± 0.02b 1.01 ± 0.02e 0.27 ± 0.01b 0.31 ± 0.01e 1.16 ± 0.03b 1.34 ± 0.02e 0.39 ± 0.01b 0.6 ± 0.04e
1.0 0.91 ± 0.02c 1.08 ± 0.05f 0.28 ± 0.01c 0.33 ± 0.01f 1.23 ± 0.03c 1.41 ± 0.04f 0.44 ± 0.03c 0.68 ± 0.01f
DAB (%) Photosynthetic rate
(µmol CO2/m2/s)
Transpiration rate
(mmol H2O/m2/s)
Stomatal Conductance
(mol H2O/m2/S)
Electrolyte Leakage
(%)
Field Capacity 70
018.87 ± 0.16a 21.72 ± 0.67c 1.27 ± 0.03a 1.55 ± 0.04d 2.05 ± 0.02a 2.32 ± 0.02d 40.27 ± 0.99c 34.26 ± 0.54e
0.5 20.23 ± 0.27b 22.77 ± 0.11d 1.46 ± 0.01c 1.72 ± 0.02f 2.24 ± 0.03c 2.47 ± 0.03f 35.48 ± 0.22a 26.9 ± 0.75cd
1.0 19.34 ± 0.19a 22.31 ± 0.14cd 1.38 ± 0.03b 1.65 ± 0.03e 2.14 ± 0.02b 2.38 ± 0.02e 37.05 ± 0.91b 30.74 ± 1.47d
Drought Stress
015.22 ± 0.13a 17.21 ± 0.48d 0.92 ± 0.03a 1.12 ± 0.01d 1.27 ± 0.03a 1.63 ± 0.07d 58.93 ± 0.27b 50.8 ± 2.70d
0.5 15.74 ± 0.26b 17.86 ± 0.1e 1 ± 0.03b 1.15 ± 0.02d 1.4 ± 0.06b 1.75 ± 0.03e 57.78 ± 0.56a 44.03 ± 0.5d
1.0 16.38 ± 0.18c 18.47 ± 0.21f 1.08 ± 0.03c 1.22 ± 0.02e 1.52 ± 0.04c 1.93 ± 0.06f 55.46 ± 1.77a 42.6 ± 0.62c
Values are mean ± standard deviation (n = 3)
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Page 10 of 20
Danish et al. BMC Plant Biology (2024) 24:139
the control group (0 DAB + 0 CMC) exhibited a reduced
chlorophyll b content of 0.26 mg/g. e introduction
of 25 CMC during drought stress resulted in a notable
15.38% increase in chlorophyll b content compared to the
control, and with the 0.5 DAB treatment 3.85% increase
was recorded. When both 0.5 DAB and 25 CMC treat-
ments were combined during drought stress, a signicant
19.23% increase in chlorophyll b content was recorded.
e 1 DAB treatment also demonstrated an increase of
7.69% in chlorophyll b content contrasted to the control
under drought stress. Notably, when 1 DAB was com-
bined with 25 CMC during drought stress, there was a
substantial 26.92% increase in chlorophyll b content rela-
tive to the control.
Under 70 FC conditions, the control group (0 DAB + 0
CMC) exhibited a mean total chlorophyll content of
1.48 mg/g. ere was a 13.51% increase in total chlo-
rophyll content when 25 CMC was added in compari-
son with the control over 70 FC. In addition, treatment
with 0.5 DAB led to a rise in total chlorophyll content
of 8.78%, while treatment with 0.5 DAB and 25 CMC
together yielded a substantial boost in total chlorophyll
content of 20.95% as compared to the control under 70
FC. Under 70 FC scenarios, the use of 1 DAB induced a
5.41% rise in total chlorophyll, while the combination of
1 DAB plus 25 CMC treatment yielded a 15.54% boost in
total chlorophyll content in comparison to the control.
Under drought stress conditions, the control group (0
DAB + 0 CMC) had a mean total chlorophyll content of
1.08mg/g. With the introduction of 25 CMC, there was a
notable 19.44% increase in total chlorophyll content, and
the application of 0.5 DAB during drought stress led to a
7.41% increase in total chlorophyll content from the con-
trol. e usage of 1DAB treatment under drought stress
scenarios resulted in a 13.89% rise in total chlorophyll
content, while the combination treatment of 0.5 DAB and
25 CMC produced a signicant 24.07% increase in total
chlorophyll content over the control. When 1 DAB was
combined with 25 CMC, there was a remarkable 30.56%
increase in total chlorophyll content under drought stress
from the control.
In the 70 FC condition, the mean carotenoid content
was 0.76mg/g for the control group (0 DAB + 0 CMC).
When 25 CMC was introduced, there was a 9.21%
increase in carotenoid content, and the application of 0.5
DAB led to a 6.58% increase in carotenoid content over
the control under no drought stress (70 FC). while com-
bining 0.5 DAB with 25 CMC resulted in a substantial
15.79% increase, and 1 DAB treatment showed a slight
1.32% increase in carotenoid content over the control
under 70 FC. When combined with 1DAB + 25CMC
treatment, a 13.16% increase was observed over the con-
trol under no stress (70 FC). In contrast, under drought
stress conditions, the control group (0 DAB + 0 CMC )
exhibited a mean carotenoid content of 0.31mg/g. e
introduction of 25 CMC during drought stress resulted
in a remarkable 67.74% increase in carotenoid content
and the application of 0.5 DAB treatment under drought
stress conditions led to a signicant 25.81% increase from
the control. Combining 0.5 DAB with 25 CMC during
drought stress induced a substantial 93.55% increase in
carotenoid content than the control. e 1 DAB treat-
ment during drought stress showed a noTable 41.94%
increase, and when combined with 25 CMC, a remark-
able 119.35% increase was observed over the control
(Table5).
Photosynthetic rate, transpiration rate, stomatal
conductance, and leave nitrogen
e photosynthetic rates of the control group were exam-
ined at 18.87 µmol CO2/m²/s under 70 FC with no DAB
and 0 CMC. When 25 CMC treatment was applied, there
was a notable 15.10% in photosynthetic rates increase
over the control under 70 FC. Similarly, the application
of 0.5 DAB resulted in a 7.21% increase and 0.5 DAB with
25 CMC showed a substantial 20.67% increase in photo-
synthetic rates in contrast to the control under no stress
(70 FC). For 1 DAB treatment, there was a modest 2.49%
increase, and treatment 1DAB was combined with 25
CMC, resulting in a notable 18.23% increase observed
over the control in photosynthetic rates under 70 FC.
Under drought stress, the control group (0 DAB + 0
CMC) exhibited a photosynthetic rate of 15.22 µmol
CO2/m²/s. e introduction of 25 CMC resulted in a sig-
nicant 13.07% increase and the application of 0.5 DAB
showed a minor 3.42% increase in photosynthetic rates
than the control under drought stress. Combining 0.5
DAB with 25 CMC demonstrated a substantial 17.35%
increase and the use of 1 DAB treatment during drought
stress led to a 7.62% increase in photosynthetic rates over
the control. Remarkably, when 1 DAB was combined
with 25 CMC, there was a substantial 21.35% increase
in photosynthetic rates compared to the control under
drought-stress conditions.
In the 70FC (non-stress) environment, the mean tran-
spiration rate for the control group (0 DAB + 0 CMC )
was 1.27 mmol H2O/m2/s. When 25 CMC treatment
was applied, there was a notable 22.05% increase in the
mean transpiration rate related to the control under
40FC. Similarly, the application of 0.5 DAB treatment
resulted in a 14.96% increase in transpiration rate, while
combining 0.5 DAB with 25 CMC led to a substantial
35.43% increase over the control under 70FC. Addition-
ally, 1 DAB treatment under drought stress showed an
8.66% rise in transpiration rate, and when combined 1
DAB with 25 CMC, showed a 29.92% raised in compari-
son to the control under no drought stress (70 FC) condi-
tions. Under drought stress conditions, the control group
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Page 11 of 20
Danish et al. BMC Plant Biology (2024) 24:139
(0 DAB + 0 CMC) exhibited a mean transpiration rate of
0.92 mmol H2O/m2/s. When 25CMC was applied during
drought stress, there was a signicant 21.74% increase in
transpiration rate compared to the control. e use of 0.5
DAB during drought stress resulted in an 8.70% increase
in transpiration rate, and when combined with 25 CMC,
there was a 25.00% increase in transpiration rate from the
control. Furthermore, 1 DAB treatment during drought
stress showed a 17.39% increase in transpiration rate,
while the combination of 1 DAB with 25 CMC resulted
in a remarkable 32.61% increase in transpiration rate
equated to the control under drought stress conditions.
Stomatal conductance in the control group with no
CMC and no DAB was recorded to be 2.05mol H2O/m2/s
under 70 FC. With the application of treatment 0.5
DAB + 25 CMC, representing a percentage increase of
20.49% over the control. Particularly, the addition of 25
CMC alone resulted in a 13.17% increase in stomatal
conductance compared to the control, whereas 0.5 DAB
contributed to a 9.27% increase under no drought stress
(70 FC). e use of 1 DAB and 1 DAB + 25 CMC treat-
ments demonstrated more modest increases of 4.39%
and 16.10%, respectively, relative to the control under
70FC conditions. In contrast, under drought stress con-
ditions, the control group showed an average stomatal
conductance of was1.27 H2O/m2/s without CMC and
DAB. e addition of 25 CMC during drought stress led
to a substantial 28.35% increase in stomatal conductance
contrasted to the control. Likewise, the application of 0.5
DAB and 0.5 DAB + 25 CMC treatments under drought
stress resulted in noticeable increases of 10.24% and
37.80%, respectively, over the control. e use of 1 DAB
treatment showed a 19.69% increase, while the combina-
tion of 1 DAB + 25 CMC treatment recorded a remark-
able 51.97% increase in stomatal conductance relative to
the control under drought stress conditions.
In the absence of both DAB and CMC (0 DAB + 0
CMC) in the 70 FC contexts, the baseline leaf N% mea-
sured 0.15%. Introducing 25CMC treatment under 70
FC conditions resulted in a noticeable 13.33% increase
in leaf N% over the control. Similarly, applying treatment
0.5DAB, resulted in a 6.67% increase, and the combina-
tion of 0.5 DAB and 25 CMC led to a 13.33% increase
in leaf N% above the control under no drought stress
(70FC). In addition, using 1 DAB under 70 FC circum-
stances increased leaf N% by 6.67%, whereas combining
1 DAB with 25 CMC resulted in a signicant 13.33% rise
in leaf N%. Under drought stress conditions, the baseline
leaf N% without any treatments (0 DAB + 0 CMC) was
0.13%. However, adding 25 CMC during drought stress
induced a 7.69% increase in leaf N% in contrast to the
control. Furthermore, applying 0.5 DAB alone or in com-
bination with 25 CMC resulted in a 7.69% and 15.38%
increase in leaf N%, respectively over the control under
drought stress. Additionally, the use of 1 DAB during
drought stress conditions led to a 7.69% increase in leaf
N%, while combining 1 DAB with 25 CMC showed a sub-
stantial 15.38% increase in leaf N% related to the control
treatment (Table5).
Leaves phosphorus and potassium
In no drought stress (70 FC), the control group (0
DAB + 0 CMC) showed a leaf P content of 0.15%. When
treatment 25 CMC was applied, there was a mod-
est increase of 6.67% in leaf P content over the control
group under 70 FC (Fig.2). Conversely, the application
of 0.5 DAB no change in leaf phosphorus content under
70 FC. However, when both 0.5 DAB and 25 CMC were
combined, there was a notable 13.33% increase in leaf P
content equaled to the control under no drought stress
(70 FC). e highest increase was observed when 1
DAB was applied, resulting in a substantial 20.00% rise,
and the combination of 1 DAB plus 25 CMC showed
a 13.33% increase in leaf P content than the control
under no drought stress (70 FC). e control group (0
DAB + 0 CMC) exhibited a leaf P content of 0.10%, which
increased by 10.00% when 25 CMC was added. e appli-
cation of 0.5 DAB showed no signicant changes over the
control under drought stress. However, when 0.5 DAB
was combined with 25 CMC under drought stress, there
was a substantial 20.00% increase in leaf P content rela-
tive to the control. e application of 1 DAB resulted in
no signicant changes or in combination with 25 CMC
also resulted in a 20.00% increase in leaf P content com-
pared to the control under drought stress conditions.
Under 70FC stress, the control group (0 DAB + 0 CMC)
exhibited a leaf K value of 0.78 (%), while the introduc-
tion of 25 CMC treatment led to a 38.46% increase in
comparison to the control under no drought stress (70
FC) (Fig.1). When 0.5 DAB treatment was applied, there
was a 29.49% increase in leaf K content, and the combi-
nation of 0.5 DAB with 25 CMC resulted in a substantial
53.85% increase in leaf K content over the control under
70 FC. Furthermore, 1 DAB treatment showed a 14.10%
increase and when 1DAB was combined with 25 CMC,
there was a signicant 44.87% increase in leaf K content
recorded over the control under no stress (70 FC). Under
drought stress conditions, the control group (0 DAB + 0
CMC) had a leaf K content of 0.31 (%). e addition of
25 C MC treatment resulted in a remarkable 61.29%
increase, and when 0.5 DAB treatment was applied dur-
ing drought stress, there was a 19.35% increase in leaf
K content in comparison to the control. Combining 0.5
DAB with 25 CMC led to a substantial 87.10% increase
in leaf K content over the control under drought stress.
Moreover, 1 DAB treatment showed a 35.48% increase
and when treatment 1 DAB was combined with 25 CMC
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Page 12 of 20
Danish et al. BMC Plant Biology (2024) 24:139
during drought stress, there was a remarkable 112.90%
increase in leaf K content contrasting to the control.
Root potassium, electrolyte leakage, root nitrogen, and
root phosphorus
e control group (0 DAB + 0 CMC) had a root K con-
tent of 0.57% under 70 FC conditions, while the addition
of 25 CMC resulted in a 14.04% increase in root K con-
tent (Table6). e application of 0.5 DAB led to an 8.77%
increase and when 0.5 DAB was combined with 25 CMC,
there was a signicant 26.32% increase in root K content
over the control under 70 FC). Similarly, 1DAB treatment
showed a 5.26% increase in root K and when 1DAB was
combined with 25 CMC, it led to a 21.05% increase in
root K content than the control under 70FC conditions.
Under drought stress conditions, the control group (0
DAB + 0 CMC) had a root K value of 0.41%. e addition
of 25 CMC resulted in a substantial 19.51% increase in
root K related to the control under drought stress. e
application of 0.5DAB led to a 7.32% increase in root K
and when 0.5DAB was combined with 25 CMC, there
was a remarkable 26.83% increase in root K related to the
control under drought stress. Similarly, 1 DAB treatment
showed a 14.63% increase in root K, and when combined
with 25 CMC, it led to an impressive 31.71% increase in
root K in comparison to the control under drought stress
conditions.
In 70FC, the control group with 0 DAB + 0 CMC exhib-
ited a mean electrolyte leakage percentage of 40.27%.
When 25 CMC was introduced under 70 FC conditions,
there was a 17.54% decrease in electrolyte leakage com-
pared to the control (Table 6). Similarly, applying 0.5
DAB resulted in a 13.50% decrease in electrolyte leak-
age evaluated to the control, and when combined with 25
CMC, there was a substantial 49.70% decrease in electro-
lyte leakage under 70 FC. e application of 1 DAB under
Fig. 2 The eect of carboxymethyl cellulose (CMC) and deashed biochar (DAB) leaf nitrogen (A), phosphorus (B) and potassium (C) of maize cultivated
under no drought and drought stress. Dots on lines are mean of n = 3
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 13 of 20
Danish et al. BMC Plant Biology (2024) 24:139
70 FC conditions led to an 8.69% decrease in electrolyte
leakage, and when combined with 25 CMC, there was a
signicant 31.00% decrease in electrolyte leakage related
to the control. Under drought stress conditions, the con-
trol group with 0 DAB + 0 CMC had a mean electrolyte
leakage of 58.93%. Introducing 25CMC during drought
stress resulted in a 16.00% decrease in electrolyte leak-
age associated with the control. In contrast, applying
0.5 DAB during drought stress showed only a modest
1.99% decrease in electrolyte leakage in comparison
to the control. However, when 0.5 DAB was combined
with 25 CMC, there was a substantial 33.84% decrease
in electrolyte leakage under drought stress from the con-
trol. e use of 1 DAB under drought stress conditions
led to a 6.26% decrease in electrolyte leakage, and when
combined with 25 CMC, there was a remarkable 38.33%
decrease in contrast to the control.
e mean value of the control group (0 DAB + 0 CMC)
exhibited a root N value of 0.040 (%). Under no drought
(70 FC), all treatments, including 25 CMC, 0.5 DAB,
and 1 DAB, exhibited no signicant percentage change
in root N% compared to the control (Table6). However,
when 0.5 DAB was combined with 25 CMC under 70 FC,
there was a noTable25.00% increase in root N% over the
control and a 25.00% increase was observed when 1 DAB
and 25 CMV treatment was combined. Under drought
stress conditions, the control (0 DAB + 0 CMC) exhibited
a root N% of 0.030%. Similarly, the addition of 25 CMC
or 0.5 DAB alone did not lead to any signicant percent-
age change in root N% over the control under drought
stress. However, when 0.5 DAB was combined with 25
CMC under drought stress, a substantial 33.33% increase
in root N% was observed in comparison to the control
under drought stress. Additionally, the application of
1DAB treatment showed no specic change or in combi-
nation with 25 CMC also resulted in a 33.33% increase in
root N% under drought stress over the control.
Under 70FC conditions with no DAB and CMC (0
DAB + 0 CMC), the mean root P (%) was 0.14%. When
25 CMC was introduced under 70FC conditions, there
was a notable increase of 21.43% in root P (%) contrasted
to the control (Table6). Similarly, the application of 0.5
DAB in 70 FC conditions resulted in a 14.29% increase
in root P relative to the control, while the combina-
tion of 0.5 DAB and 25CMC led to a substantial 42.86%
increase in root P assessed to the control. e use of 1
DAB under 70 FC conditions showed a 7.14% increase in
root P (%) compared to the control, and when 1 DAB was
combined with 25 CMC, there was a signicant 28.57%
increase in root P. In contrast, under drought stress con-
ditions with no DAB and CMC (0 DAB + 0 CMC), the
root P was much lower at 0.04%. However, when 25 CMC
was applied under drought stress, there was a remark-
able 125.00% increase in root P contrasted to the control.
Table 6 The eect of carboxymethyl cellulose (CMC) and deashed biochar (DAB) on catalase, ascorbate peroxidase (APx), hydrogen peroxide (H2O2) and malondialdehyde (MDA) of
maize cultivated under no drought and drought stress
DAB
(%)
Catalase
(CAT )
(U/mg Protein)
Ascorbate peroxidase (APx)
(U/mg Protein)
Hydrogen peroxide
(H2O2)
(n mol/g FW)
Malondialdehyde (MDA)
(nmol/mg Protein)
Peroxidase
(POD)
(U/mg Protein)
0 CMC 25 CMC 0 CMC 25 CMC 0 CMC 25 CMC 0 CMC 25 CMC 0 CMC 25 CMC
Field Capacity 70
048.56 ± 1.12c 38.1 ± 1.04e 3.4 ± 0.10b 2.83 ± 0.07d 32.87 ± 0.51c 24.62 ± 1.17e 0.8 ± 0.04b 0.5 ± 0.03e 29.32 ± 0.54c 23.05 ± 1.18e
0.5 41.04 ± 0.88a 27.29 ± 1.38c 2.98 ± 0.04a 2.63 ± 0.05c 27.12 ± 0.53a 13.51 ± 0.81d 0.59 ± 0.02a 0.31 ± 0.04c 26.54 ± 1.27a 16.22 ± 0.62d
1.0 44.44 ± 1.07b 31.3 ± 2.21d 3.06 ± 0.04ab 2.73 ± 0.01c 28.93 ± 0.01b 21.02 ± 1.0d 0.69 ± 0.03a 0.38 ± 0.04d 28.01 ± 0.22b 19.98 ± 1.14de
Drought Stress
077.34 ± 1.15c 65.66 ± 1.6f 4.94 ± 0.04b 4.04 ± 0.15d 53.3 ± 0.69c 42.26 ± 1.02f 1.44 ± 0.04c 1.11 ± 0.06f 41.85 ± 1.24c 34.73 ± 0.37f
0.5 73.42 ± 1.14b 58.96 ± 2.18e 4.82 ± 0.04a 3.7 ± 0.10d 51.29 ± 0.93b 38.51 ± 1.63e 1.32 ± 0.04b 0.98 ± 0.06e 39.42 ± 1.11b 32.88 ± 0.55e
1.0 70.11 ± 1.39a 52.88 ± 2.21d 4.53 ± 0.16a 3.58 ± 0.03c 47.96 ± 1.71a 35.95 ± 0.84d 1.24 ± 0.03a 0.88 ± 0.03d 36.26 ± 0.90a 31.33 ± 0.66d
Values are mean ± standard deviation (n = 3)
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Danish et al. BMC Plant Biology (2024) 24:139
Similarly, the application of 0.5DAB during drought
stress resulted in a 25.00% increase in root P, and when
combined with 25 CMC, a substantial 175.00% increase
in root P was observed over the control. e use of 1
DAB under drought stress conditions showed a 100.00%
increase in root P relative to the control, and when 1
DAB was combined with 25 CMC, there was a remark-
able 200.00% increase in root P (Fig.3).
Peroxidase and superoxidase
Under no stress (70FC), the control group with no DAB
or CMC (0 DAB + 0 CMC) exhibited a mean POD activ-
ity of 29.32 U/mg protein (Fig. 2). When 25CMC was
introduced in the 70FC conditions, there was a decrease
of 27.20% in POD activity in comparison to the con-
trol. Conversely, the application of 0.5 DAB treatment
resulted in a 10.47% decrease in POD activity related to
the control under 70 FC. e combination of 0.5 DAB
and 25 CMC led to a substantial 80.76% decrease in POD
activity under 70FC contrasted to the control. When
1 DAB was used under 70 FC conditions, POD activity
decreased by 4.68%, and when 1 DAB was combined with
25CMC, POD activity decreased signicantly by 46.75%
in comparison to the control. Under drought stress con-
ditions, the control group (0 DAB + 0 CMC) exhibited a
higher mean POD activity of 41.85 U/mg protein. e
introduction of 25 CMC during drought stress caused a
20.50% decrease in POD activity over the control treat-
ment. Meanwhile, applying 0.5 DAB during drought
stress led to a 6.16% decrease in POD activity related to
the control. e combination of 0.5 DAB and 25 CMC
during drought stress resulted in a 27.28% decrease in
POD activity related to the control. Finally, the use of 1
DAB during drought stress conditions showed a 15.42%
decrease in POD activity, and when combined with 25
CMC, there was a notable 33.58% decrease in POD activ-
ity relative to the control.
Fig. 3 The eect of carboxymethyl cellulose (CMC) and deashed biochar (DAB) roots nitrogen, phosphorus and potassium of maize cultivated under no
drought and drought stress. Dots on lines are mean of n = 3
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 15 of 20
Danish et al. BMC Plant Biology (2024) 24:139
In the absence of DAB and CMC (0 DAB + 0 CMC) in
a 70 FC, SOD activity was recorded at 19.48 U/mg pro-
tein (Fig.2). e addition of 25 CMC treatment resulted
in an 11.76% decrease in SOD activity over the control
under 70 FC. When 0.5DAB was introduced, there was
a 5.41% decrease in SOD activity evaluated to the control
under 70 FC. e combination of 0.5 DAB and 25 CMC
exhibited a substantial 34.44% decrease in SOD activity,
and the application of 1 DAB led to a signicant 1.30%
decrease in SOD activity in comparison to the control
under 70 FC. However, when 1DAB was combined with
25 CMC as compared to the control in 70 FC, there was a
notable 21.30% decrease in SOD activity. Under drought
stress conditions, the absence of both DAB and CMC (0
DAB + 0 CMC) led to a SOD activity of 24.80 U/mg pro-
tein. e introduction of 25CMC during drought stress
resulted in a 12.22% decrease in SOD activity related
to the control. When 0.5 DAB was applied, SOD activ-
ity decreased slightly by 1.39% over the control under
drought stress. Combining 0.5 DAB with 25 CMC exhib-
ited a 15.89% decrease in SOD activity and the appli-
cation of 1 DAB during drought stress led to a 6.26%
decrease in SOD activity in contrast to the control. Addi-
tionally, when 1 DAB was combined with 25 CMC during
drought stress, there was a signicant 19.40% decrease in
SOD activity related to the control.
Catalase activity, ascorbate, hydrogen peroxidase
and malondialdehyde
Under non-drought stress conditions (70FC), the control
group (0DAB + 0CMC) exhibited a CAT activity of 48.56
U/mg protein. When 25 CMC was introduced, there was
a 27.45% decrease in CAT activity from the control under
70FC and the application of 0.5 DAB led to an 18.32%
decrease in CAT activity. e most substantial change
was observed when both 0.5 DAB and 25 CMC were
combined, resulting in a remarkable 77.94% decrease in
CAT activity over the control under 70 FC condition.
On the other hand, related to the control, when 1DAB
was applied under 70FC, there was a 9.27% decrease in
CAT activity. When 1DAB was combined with 25CMC,
a signicant 55.14% decrease in CAT activity was
observed compared to the baseline treatment under 70
FC. Under drought stress conditions, the control group
(0 DAB + 0 CMC) exhibited a CAT activity of 77.34 U/
mg protein. With the addition of 25CMC, there was a
17.79% decrease in CAT activity, and the application of
0.5DAB led to a modest 5.34% decrease in CAT activity
in contrast to the control under drought stress. When
both 0.5 DAB and 25 CMC were combined, a substan-
tial 31.17% decrease in CAT activity was observed under
drought stress over the control. Conversely, when 1 DAB
was applied during drought stress, there was a 10.31%
increase in CAT activity, and the combination of 1 DAB
and 25 CMC showed a notable 46.26% increase in CAT
activity under drought stress contrasting to the control.
e addition of 25 CMC treatment led to a 20.14%
drop in APx activity under non-drought stress conditions
(70 FC), whereas the application of 0.5 DAB treatment
showed a 14.09% reduction as compared to the control.
When both 0.5 DAB and 25 CMC were combined, there
was a substantial 29.28% decrease in APx activity asso-
ciated with the control in 70FC. However, the use of 1
DAB in the same conditions caused an 11.11% decrease
in APx activity, and when combined with 25 CMC, there
was a 24.54% decrease related to the control under 70FC.
Under drought stress, the control group of APx activity
was recorded to be 4.94 U/mg protein. e addition of
25 CMC led to a 22.28% decrease in APx activity, while
0.5 DAB produced only a slight 2.49% decrease in APx
activity over the control under drought stress. However,
when 0.5 DAB and 25CMC were used together under
drought stress, there was a signicant 33.51% decrease
in APx activity linked to the control. On the other hand,
the application of 1 DAB during drought stress resulted
in a 9.05% decrease in APx activity, and when combined
with 25 CMC, there was a remarkable 37.99% decrease as
compared to the control.
Under 70FC, the control group (0 DAB + 0 CMC) had
H2O2 levels at 32.87 nmol/g FW. When 25 CMC was
introduced, there was a 33.51% decrease in H2O2 lev-
els contrasted to the control under 70FC. Similarly,
the application of 0.5 DAB resulted in a 21.20% reduc-
tion in H2O2 levels, and when combined with 25 CMC
under 70 FC, there was a signicant 143.30% decrease
in H2O2 levels associated with the control. In contrast, 1
DAB led to a 13.62% decrease in H2O2 levels, and when
combined with 25 CMC, there was a 56.37% decrease in
H2O2 levels contrasted to the control under 70 FC condi-
tions. Under drought stress conditions, the control group
(0DAB + 0CMC) showed H2O2 levels at 53.30 nmol/g FW.
When 25CMC was applied, there was a 26.12% decrease
in H2O2 levels contrasted to the control under drought
stress. e use of 0.5 DAB resulted in a 3.92% decrease
in H2O2 levels, while the combination of 0.5 DAB and 25
CMC led to a signicant 38.41% decrease in H2O2 levels
over to the control under drought stress. Similarly, 1 DAB
resulted in an 11.13% decrease in H2O2 levels, and when
combined with 25 CMC, there was a substantial 48.26%
decrease in H2O2 levels compared to the control under
drought stress conditions.
e control group (0 DAB + 0 CMC) had MDA levels of
0.80 nmol/mg protein at 70FC conditions. Under 70 FC
conditions, the application of 25 CMC led to a signicant
60.00% decrease in MDA levels contrasted to the control.
Similarly, when 0.5 DAB was applied under 70 FC con-
ditions, there was a noTable 35.59% reduction in MDA
levels over the control under 70FC. e combination of
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Danish et al. BMC Plant Biology (2024) 24:139
0.5 DAB and 25 CMC resulted in a 158.06% decrease in
MDA levels associated with the control compared to the
control under no stress (70 FC). On the other hand, the
use of 1 DAB under 70 FC conditions led to a moderate
15.94% decrease in MDA levels, while the combination of
1 DAB and 25 CMC decreased MDA levels by 110.53%
relative to the control. Under drought stress conditions,
the application of 25 CMC resulted in a 29.73% decrease
in MDA levels compared to the control (0 DAB + 0
CMC). When 0.5 DAB was applied during drought stress,
there was a slight 9.09% decrease in MDA levels relative
to the control. However, when 0.5 DAB was combined
with 25 CMC under drought stress, a signicant 46.94%
decrease in MDA levels was observed over the control.
Similarly, the use of 1 DAB under drought stress condi-
tions decreased MDA levels by 16.13%, while the com-
bination of 1 DAB and 25 CMC led to a substantial
63.64% decrease in MDA levels contrasted to the control
(Table6).
Convex hull, hierarchical cluster analysis
e convex hull analysis reveals distinct clusters of data
points for the two categories, Drought Stress and 70FC.
For Drought Stress, the convex hull spans from a mini-
mum PC 1 value of -8.85218 to a maximum of 0.00823,
and from a low PC2 value of -0.53011 to a high of 0.65704.
Within this convex hull, 97.54% of the data points fall
under the drought stress category. On the other hand, the
convex hull for 70FC ranges from a minimum PC1 value
of 0.00823 to a maximum of 8.90135, and from a low PC2
value of -0.69592 to a high of 0.82322. Interestingly, all
data points associated with 70 FCare enclosed within this
convex hull, indicating 100% coverage (Fig.4A).
The results of the convex hull analysis conducted
on the provided dataset are as follows: In the PC1-
PC2 space, data points were systematically catego-
rized into distinct Drought Stress levels based on their
specific positions within the convex hull. Notably, the
analysis found that 97.54% of the data points were situ-
ated within the confines of the convex hull associated
Fig. 4 Cluster plot convex hull for stress (70FC) (A), deashed biochar (DAB) (B), carboxymethyl cellulose (CMC) (C), and hierarchical cluster plot (D) for
studied attributes
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Page 17 of 20
Danish et al. BMC Plant Biology (2024) 24:139
with the 0 DAB Drought Stress category. Additionally,
0.94% of the data points belonged to this same cate-
gory, yet they fell outside the convex hull’s boundaries.
The assignment of Drought Stress labels to individual
data points hinged on their precise coordinates within
the convex hull. For example, data points featuring
PC1 and PC2 coordinates of -8.85218 and 0.61202,
respectively, were categorized as 0 DAB since they
were located within the convex hull delineated for this
specific Drought Stress level. Likewise, data points
exhibiting coordinates such as -5.97378 for PC1 and
0.35776 for PC2 were designated as 1DAB as they were
found within the convex hull corresponding to that
Drought Stress category (Fig.4B).
The results of the analysis, which involves convex
hull calculations and drought stress scores, are pre-
sented in a concise and organized manner. In the data-
set, two principal components (PC 1 and PC 2) are
associated with drought stress, specifically DAB and
CMC. The Drought Stress values are represented as
percentages, with PC 1 having a dominance of 97.54%
and PC 2 contributing 0.94%. The subsequent section
of the results presents scores and associated labels.
These scores are numerical values that likely pertain to
the analysis. The labels categorize the scores into two
main groups, 0 CMC and 25 CMC, which may signify
different experimental conditions or states. Within
the 0CMC category, scores range from − 8.85218 to
4.05187, with corresponding PC 1 and PC 2 values. It’s
evident that these scores represent a specific condi-
tion, possibly related to the absence of a certain factor
denoted as CMC. On the other hand, the 25 CMC cat-
egory encompasses scores spanning from − 4.53349 to
8.90135, accompanied by PC 1 and PC 2 values. This
suggests an alternate experimental condition or treat-
ment where CMC appears to be present or relevant
(Fig.4C).
Hierarchical cluster analysis was applied to evalu-
ate a dataset featuring two principal components, PC
1 and PC 2, alongside their associated Drought Stress
values. The outcome of this analysis unveiled a hier-
archical structure of clusters rooted in the similar-
ity between variables. The dataset was segmented
into 24 distinctive clusters. It’s worth noting that cer-
tain clusters exhibited a consistent level of similarity
among their constituent variables, such as Cluster 1
and Cluster 2, boasting relatively low similarity values
of 0.15041 and 0.2049, respectively. Conversely, Clus-
ter 23 attracted attention due to its exceptionally high
similarity values, indicating a distinctive cluster of
variables. Moreover, several clusters, including Cluster
11 and Cluster 14, displayed varying similarity values
among their members. Additionally, the analysis iden-
tified individual variables that did not form substantial
groups with others, such as variable 57, which consti-
tuted Cluster 24 independently (Fig.4D).
Pearson correlation
The results of the Pearson correlation analysis con-
ducted on various plant growth and physiological
parameters reveal significant relationships among
these variables (Fig. 4). The correlation matrix pro-
vides insights into the strength and direction of these
associations. Shoot length (cm) exhibited strong
positive correlations with several parameters, includ-
ing shoot fresh weight (0.98635), shoot dry weight
(0.99123), root fresh weight (0.98518), and root dry
weight (0.9944), suggesting that longer shoot lengths
are associated with higher shoot and root weights.
Additionally, shoot length also displayed positive cor-
relations with the number of leaves (0.97879) and vari-
ous chlorophyll measurements, such as chlorophyll a
(0.98738) and chlorophyll b (0.98205), indicating that
increased shoot length may coincide with greater
chlorophyll content and leaf production. The relation-
ship between shoot fresh weight and shoot dry weight
was notably strong (0.98635), illustrating a close cor-
respondence between these two-growth metrics. Fur-
thermore, shoot fresh weight and shoot dry weight
exhibited high positive correlations with most other
parameters, including root fresh weight, root dry
weight, and leaf attributes like leaf fresh weight, leaf
dry weight, and total chlorophyll content. Chlorophyll
measurements, including chlorophyll a, chlorophyll b,
and total chlorophyll, displayed strong positive cor-
relations with one another, with coefficients ranging
from 0.98044 to 0.99469, indicating that higher levels
of one type of chlorophyll are often associated with
increased levels of the others. This suggests a coordi-
nated relationship in chlorophyll production within
the plant. Photosynthetic rate (µmol CO2/m2/S) and
transpiration rate (mmol H2O/m2/S) exhibited a very
strong positive correlation (0.99502), indicating that
as photosynthetic rate increases, so does transpira-
tion rate, reflecting the interconnectedness of these
processes in plant physiology. In contrast, electrolyte
leakage showed negative correlations with most of the
parameters, suggesting that higher electrolyte leakage,
which can indicate cell damage or stress, tends to coin-
cide with lower values in the measured plant growth
and physiological attributes (Fig.5).
Discussion
The study delved into various physiological markers,
including chlorophyll content, carotenoid presence,
photosynthetic activity, transpiration rate, stomatal
conductivity, and electrolyte leakage. Both CMC and
DAB treatments positively influenced these traits,
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Page 18 of 20
Danish et al. BMC Plant Biology (2024) 24:139
suggesting heightened photosynthesis efficiency,
potentially linked to increased nutrient uptake and
improved soil water availability facilitated by these
amendments.
The decrease in stomatal conductance and transpira-
tion rate indicated a potential reduction in water loss,
particularly crucial under drought-stress conditions
(Table5) [35]. This adaptive response enables the plant
to conserve water, sustain turgor pressure, and allocate
more resources to growth and stress tolerance mecha-
nisms, particularly in drought-stressed scenarios [36].
The research also provided valuable insights into
the biochemical and physiological responses of maize
plants to field capacity and drought stress [37]. Under
optimal field conditions, enzymatic activities and oxi-
dative stress parameters remained balanced (Table6),
reflecting a well-regulated antioxidant defense mecha-
nism [38]. However, during drought stress, significant
changes in enzymatic activity and oxidative stress indi-
cators were observed, illustrating the plant’s adaptive
responses to water scarcity.
e increased activity of antioxidant enzymes like per-
oxidase (POD) [39], superoxide dismutase (SOD), cata-
lase, and ascorbate peroxidase (APX) indicated the plant’s
eorts to mitigate oxidative stress caused by elevated
reactive oxygen species (ROS) levels during drought
stress (Table 6). e study highlighted the importance
of these mechanisms in protecting cellular components
from damage [40].
Furthermore, the research emphasized the need to
comprehend these physiological responses when devel-
oping strategies to enhance plant resilience in drought-
prone environments. e ndings suggested that the
use of CMC and DAB could signicantly improve maize
development and physiological responses, particularly
in drought-stressed conditions, by enhancing soil water
retention, improving soil structure, increasing nutrient
availability, and reducing water loss [41].
e practical implications of these ndings include
the potential to address challenges posed by water con-
straints and changing climatic conditions in maize
cultivation, thereby contributing to sustainable agricul-
ture [42, 43]. However, the study also underscored the
importance of further research to explore the long-term
consequences and environmental implications of these
agricultural changes, with a call for additional investiga-
tion into specic genes and processes involved in these
actions [42, 43].
Conclusion
In conclusion, the use of 1% DAB + 25mM CMC exhib-
its the capacity to enhance the growth attributes of maize
when exposed to drought conditions. e incorpora-
tion of 1% DAB + 25mM CMC has proved its capacity to
Fig. 5 Pearson correlation for studied attributes
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Page 19 of 20
Danish et al. BMC Plant Biology (2024) 24:139
enhance the uptake of essential nutrients such as nitro-
gen (N), phosphorus (P), and potassium (K) in both the
root and shoot. is nutrient enhancement signicantly
contributes to the overall improvement of maize growth
during drought-stress conditions. Furthermore, the 1%
DAB + 25 mM CMC treatment exhibits the potential
to regulate antioxidants under drought stress, thereby
potentially mitigating the adverse eects of drought on
maize. Further research at the eld level is recommended
to validate 1% DAB + 25mM CMC as the optimal treat-
ment for alleviating drought stress in maize.
Acknowledgements
This project was supported by Researchers Supporting Project number
(RSP2024R385), King Saud University, Riyadh, Saudi Arabia.
Author contributions
Conceptualization, S.D.; Z.H.; methodology, S.D.; software, writing—original
draft preparation, S.D; K.D.; S.F.; writing—review and editing, S.D.; S.H.S.; M.J.A.;
validation, S.H.S.; M.J.A.; formal and statistical analysis, K.D.; S.F.; investigation,
resources, K.D.; Z.H.; A.N.S.; data curation, investigation, S.F.; K.D.; resources, S.F.;
S.D; A.N.S.; S.H.S.; M.J.A.;
Funding
This project was supported by Researchers Supporting Project number
(RSP2024R385), King Saud University, Riyadh, Saudi Arabia.
Data availability
All data generated or analysed during this study are included in this published
article.
Declarations
Ethics approval and consent to participate
We all declare that manuscript reporting studies do not involve any human
participants, human data, or human tissue. So, it is not applicable. Study
protocol must comply with relevant institutional, national, and international
guidelines and legislation. Our experiment follows the with relevant
institutional, national, and international guidelines and legislation.
Consent for publication
Not Applicable.
Competing interests
The authors declare no competing interests.
Received: 18 September 2023 / Accepted: 21 February 2024
References
1. Jabborova D, Ziyadullaeva N, Enakiev Y, Narimanov A, Dave A, Sulaymanov K
et al. Growth of spinach as inuenced by biochar and Bacillus endophyticus
IGPEB 33 in drought condition. Pak J Bot. 2023;55:53–9. Available from: http://
pakbs.org/pjbot/paper_details.php?id=12046.
2. Hussain S, Shah MN. Organic amendments mitigate drought stress-induced
oxidative changes in synthetic cultivars of maize. Pak J Bot. 2023;55:429–36.
3. Anwar T, Shehzadi A, Qureshi H, Shah MN, Danish S, Salmen SH, et al. Allevia-
tion of cadmium and drought stress in wheat by improving growth and
chlorophyll contents amended with GA3 enriched deashed biochar. Sci Rep.
2023;13:18503.
4. Koehler T, Schaum C, Tung S-Y, Steiner F, Tyborski N, Wild AJ, et al. Above and
belowground traits impacting transpiration decline during soil drying in 48
maize (Zea mays) genotypes. Ann Bot. 2023;131:373–86.
5. Mazhar MW, Ali Q, Ishtiqa M, Ghani A, Maqbool M, Hussain T et al. ZINC-
aspartate mediated drought amelioration in maize promises better growth
and agronomic parameters than zinc sulphate and L-aspartate. SABRAO J
Breed Genet. 2021;53:210–310.
6. Joyce A, Goddek S, Kotzen B, Wuertz S. Aquaponics: closing the cycle on
limited water, land and nutrient resources. Aquaponics Food Production
Systems. Cham: Springer International Publishing; 2019. pp. 19–34.
7. Gomes LC, Bianchi FJJA, Cardoso IM, Fernandes RBA, Filho EIF, Schulte RPO.
Agroforestry systems can mitigate the impacts of climate change on coee
production: a spatially explicit assessment in Brazil. Agric Ecosyst Environ.
2020;294:106858.
8. Alotaibi MO, Ikram M, Alotaibi NM, Hussain GS, Ghoneim AM, Younis U et
al. Examining the role of AMF-Biochar in the regulation of spinach growth
attributes, nutrients concentrations, and antioxidant enzymes in mitigating
drought stress. Plant Stress. 2023;10:100205. Available from: https://linking-
hub.elsevier.com/retrieve/pii/S2667064X23000726.
9. Elahi NN, Farrukh N, ul ain, Jalaluddin S, Ahmed HM, Saima S, Mustafa S et
al. Comparing the positive impacts and stress induction by polyethylene
glycol (PEG 6000) variable levels on canola (Brassica napus L.) growth, yield,
and oil Contents. ACS Omega. 2023;8:29046–59. https://doi.org/10.1021/
acsomega.3c02066.
10. Zingore S. Integrated soil fertility management: A basis for sustainable
intensication of maize-based cropping systems of Southern Africa. 2023. p.
39–57.
11. Ahmad Ali S, Zahid Mumtaz M, Ahmad Rahi A, Irshad I, Sabir Hussain G,
Dawar K et al. Impact of acidied carbon on maize growth, yield and grains
nutrients concentration under normal irrigation and osmotic stress. J King
Saud Univ Sci. 2023;35:102505. Available from: https://linkinghub.elsevier.
com/retrieve/pii/S1018364722006863.
12. Watcharamul S, Lerddamrongchai S, Siripongpreda T, Rodtassana C, Nuisin
R, Kiatkamjornwong S. Eects of Carboxymethyl Cellulose/Nano-Calcium
Carbonate Hydrogel Amendment of Loamy Sand Soil for Maize Growth. ACS
Agricultural Science and Technology. 2022;2:1071–80.
13. Mazloom N, Khorassani R, Zohury GH, Emami H, Whalen J. Lignin-based
hydrogel alleviates drought stress in maize. Environ Exp Bot. 2020;175:104055.
14. Liu C, Gong X, Wang H, Dang K, Deng X, Feng B. Low-nitrogen tolerance
comprehensive evaluation and physiological response to nitrogen stress in
broomcorn millet (Panicum miliaceum L.) seedling. Plant Physiol Biochem.
2020;151:233–42.
15. Weber K, Quicker P. Properties of biochar. Fuel. 2018;217:240–61.
16. Shahzad AS, Younis U, Naz N, Danish S, Syed A, Elgorban AM, et al. Acidied
biochar improves lead tolerance and enhances morphological and bio-
chemical attributes of mint in saline soil. Sci Rep. 2023;13:8720.
17. Dawar K, Asif M, Irfan M, Mian IA, Khan B, Gul N et al. Evaluating the ecacy
of activated Carbon in minimizing the risk of Heavy metals Contamination in
Spinach for Safe Consumption. ACS Omega. 2023; 8: 24323–31.
18. Sun K, Kang M, Zhang Z, Jin J, Wang Z, Pan Z et al. Impact of deashing treat-
ment on biochar structural properties and potential sorption mechanisms
of phenanthrene. Environ Sci Technol. 2013;47:11473–81. https://doi.
org/10.1021/es4026744.
19. Islam MT. Hydrothermal preprocessing of waste corn stover into advanced
biorenery feedstock. Theses and Dissertations. Biomedical and Chemical
Engineering and Sciences. Florida Institute of Technology. 2022; 571.
20. Wang Z, Alinezhad A, Sun R, Xiao F, Pignatello JJ. Pre- and postapplication
thermal treatment strategies for sorption enhancement and reactivation of
biochars for removal of per- and polyuoroalkyl substances from water. ACS
ES&T Eng. 2023;3:193–200.
21. Mclaughlin H. Jan. Characterizing biochars prior to addition to soils – version
I, 2010. 2010;1–8.
22. Page AL, Miller RH, Keeny DR. Soil pH and lime requirement. In: Page AL,
editor. Methods of Soil Analysis: part 2 Chemical and Microbiological proper-
ties, 922/Agronomy monographs. 2nd ed. Madison: American Society of
Agronomy, Inc. and Soil Science Society of America, Inc.; 1983. pp. 199–208.
23. Rhoades JD. Salinity: electrical conductivity and total dissolved solids. In:
Sparks DL, Page AL, Helmke PA, Loeppert RH, Soltanpour PN, Tabatabai MA, et
al. editors. Methods of Soil Analysis, Part 3, Chemical methods. Madison, WI,
USA: Soil Science Society of America; 1996. pp. 417–35.
24. V. J. C. H. Schouwvenberg and I. Walinge. Methods of analysis for Plant Mate-
rial., Agriculture University, Wageningen. 1973.
25. Miller RO. Nitric-perchloric wet digestion in an open vessel. p. 57–62. In: Hand
Book of Reference Methods for Plant analysis, editor: Y.P. Kalra. Soil and Plant
Analysis Council Inc. CRC Press, Washington DC, USA. CRC Press: Boca Raton,
FL; 1998.
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Page 20 of 20
Danish et al. BMC Plant Biology (2024) 24:139
26. Pratt PF. Potassium. In: Norman AG, editor. Methods of Soil Analysis, Part 2:
Chemical and Microbiological properties. John Wiley & Sons, Ltd; 2016. pp.
1022–30.
27. Ahmad M, Rajapaksha AU, Lim JE, Zhang M, Bolan N, Mohan D, et al. Biochar
as a sorbent for contaminant management in soil and water: a review. Che-
mosphere. 2014;99:19–33.
28. Boutraa T, Akhkha A, Al-Shoaibi AA, Alhejeli AM. Eect of water stress on
growth and water use eciency (WUE) of some wheat cultivars (Triticum
durum) grown in Saudi Arabia. J Taibah Univ Sci. 2010;3:39–48.
29. Arnon DI. Copper enzymes in isolated chloroplasts. Polyphenoloxidase in
Beta vulgaris. Plant Physiol. 1949;24:1.
30. Nazar R. Cadmium toxicity in plants and role of mineral nutrients in its allevia-
tion. Am J Plant Sci. 2012;3:1476–89.
31. Abbas T, Rizwan M, Ali S, Zia-ur-Rehman M, Farooq Qayyum M, Abbas F, et al.
Eect of biochar on cadmium bioavailability and uptake in wheat (Triticum
aestivum L.) grown in a soil with aged contamination. Ecotoxicol Environ Saf.
2017;140:37–47.
32. van der Bom FJT, Williams A, Borrell AK, Raymond N, Bell MJ. Phosphorus
management is key to eective deployment of root ideotypes in complex
soil environments. Plant Soil. 2023; 489: 323–340.
33. Hugo A, Lester P. Catalase in vitro. Methods Enzymol. 1984;105:121–6.
34. Steel RG, Torrie JH, Dickey DA. Principles and procedures of statistics: a Bio-
metrical Approach. 3rd ed. Singapore: McGraw Hill Book International Co.;
1997.
35. Wei Z, Abdelhakim LOA, Fang L, Peng X, Liu J, Liu F. Elevated CO2 eect on the
response of stomatal control and water use eciency in amaranth and maize
plants to progressive drought stress. Agric Water Manag. 2022;266:107609.
36. Nguyen D, Van, Nguyen HM, Le NT, Nguyen KH, Nguyen HT, Le HM et al. Cop-
per nanoparticle application enhances plant growth and grain yield in maize
under drought stress conditions. J Plant Growth Regul. 2021;1–12. https://doi.
org/10.1101/2020.02.24.963132
37. Siroha AK, Punia S, Purewal SS, Sandhu KS. Millets. 1st edition. Boca Raton:
CRC Press; 2021.https://doi.org/10.1201/9781003105947
38. Luo Y, Zeng W, Lei G, Hou Y, Ao C, Chen H et al. The eects of multiwalled
carbon nanotubes and Bacillus subtilis treatments on the salt tolerance of
maize seedlings. Front Plant Sci. 2022;13.
39. Tariq M, Khan A, Asif M, Khan F, Ansari T, Shariq M, et al. Biological control: a
sustainable and practical approach for plant disease management. Acta Agric
Scand B Soil Plant Sci. 2020;70:507–24.
40. Sahu PK, Jayalakshmi K, Tilgam J, Gupta A, Nagaraju Y, Kumar A, et al. ROS
generated from biotic stress: eects on plants and alleviation by endophytic
microbes. Front Plant Sci. 2022;13:1042936.
41. Jha Y, Yadav KA, Mohamed HI. Plant growth-promoting bacteria and
exogenous phytohormones alleviate the adverse eects of drought stress in
pigeon pea plants. Plant Soil. 2023.
42. Yahaya MA, Shimelis H. Drought stress in sorghum: mitigation strate-
gies, breeding methods and technologies—A review. J Agron Crop Sci.
2022;208:127–42.
43. Mohan N, Jhandai S, Bhadu S, Sharma L, Kaur T, Saharan V, et al. Acclimation
response and management strategies to combat heat stress in wheat for
sustainable agriculture: a state-of-the-art review. Plant Sci. 2023;336:111834.
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